Stator manufacturing method

ABSTRACT

Stator coil lead wires are coursed along complex, circuitous paths on the end of a stator core and trimmed at a precise predetermined distance from the stator core. Improved end effector wire-guiding tooling members are provided in place of conventional gripper jaws to permit the lead wires to be coursed along complex, circuitous paths. In addition, an improved lead pull assembly, improved temporary wire clamps, and a wire former assembly are provided.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a division of Application Ser. No. 08/762,577, filed Dec. 9,1996, now U.S. Pat. No. 5,765,274, which claims the benefit of U.S.Provisional applications 60/022,548, filed Jun. 20, 1996, and60/017,683, filed May 21, 1996.

FIELD OF THE INVENTION

This invention relates to methods and apparatus for manufacturingelectric motor stators and, although not so limited, particularly formanufacturing two-pole stators.

INCORPORATION BY REFERENCE

The following patents and other published documents are herebyincorporated herein by reference:

U.S. Pat. No. 5,495,659

U.S. Pat. No. 5,413,403

U.S. Pat. No. 5,370,324

U.S. Pat. No. 5,186,405

U.S. Pat. No. 5,090,108

U.S. Pat. No. 4,074,418

PCT publication WO 96/34446.

BACKGROUND OF THE INVENTION

The need arises for stator coil lead wires to be anchored to a statorand cut automatically to close tolerances with regard to length, forexample, within 1 mm from a fixed reference point on the stator core.Three axis industrial robots are now commonly used to anchor or connectstator coil leads to stators, partly because of the ability to changeover robots to handle various different anchoring and cutting tasks inminimal time. Prior art lead wire trimming methods using robots to severstator coil lead wires are not generally capable of cutting leads toclose tolerances. Also, the wires used to form stator coils may exhibitdifferent degrees of stretching, which can have an effect on the lengthof the cut coil lead using typical robot lead wire connecting andcutting techniques. Therefore, there exists a need for an improvedmethod and apparatus using an industrial robot for performing suchtrimming operations within close tolerances.

There are also occasions in which the stator coil leads must be coursedthrough a complex, circuitous path along the end face of the statorcore, and the need exist for an improved method and apparatus forcoursing the stator coil leads across the face of a stator core.

SUMMARY OF THE INVENTION

An object of this invention is to provide a method and an apparatus fortrimming stator coil lead wires within close tolerances so that the coillead wires meet exacting requirements of motor manufacturers.

In another aspect of this invention, an object is to provide an improvedmethod and apparatus for coursing stator coil lead wires across andadjacent the end face of a stator core.

In yet another aspect of this invention, an object is to provideimproved wire handling structures for use in achieving the foregoingobjects.

In accordance with this invention, a stator coil lead wire is coursed bya robot end effector across the end face of the stator core, across amargin of the stator core, and then secured to an anchor radially spacedfrom the stator core. While the lead wire is secured to the anchor, thelead wire is cut, preferably by operation of the end effector, at apredetermined distance from the stator core. The anchor may be a clampor clip having opposed jaws which grip the lead wire or it may be a postaround which the lead wire is at least partially looped.

In order to better course the lead wires along a complex, circuitouspath on the stator end face, a conventional robot end effector ismodified in accordance with this invention to include opposedwire-guiding tooling members in place of the gripper jaws, therebypermitting precision control of the lead wires. In accordance with thisinvention, each opposed wire-guiding tooling member of the robot endeffector is provided with a concavely arcuate, generally C-shapedportion at its free end facing the opposite wire-guiding tooling member.When the end effector wire-guiding tooling members are closed, theconfronting C-shaped portions form a ring or eyelet that encloses a leadwire.

To better permit the improved end effector wire-guiding tooling membersto capture a coil lead to be manipulated, a ledge-like structure isprovided in the path of the coil leads inserted into temporary wireclamps at the winding station. Such ledge cause the lead wires to extendto the clamps at an artificially steep angle relative to vertical, whichmore readily permits the leads to be enclosed within the end effectoreyelet at a robot wire handling station. In addition, the coil leadsextending to the temporary wire clamps are also coursed aroundprojections, such as dowel pins or hooks, extending from the front,wire-engaging surface of the ledge to ensure that the location of eachlead wire is established with precision.

Further in accordance with this invention, various wire handlingstructures known in the art are improved to provide the desired wirehandling characteristics. An improved lead pull assembly is providedwhich permits the lead pull assembly to retain control over a lead wireeven if a slack wire condition occurs in the wire. An improved temporarywire clamp is also provided which ensures that lead wires inserted or"stuffed" therein using a tamp blade remain in the wire clamp as thetamp blade is withdrawn. Also, since the lead wires are coursed along apath on the stator core end face, wire forming tooling is providedhaving a wire former with surfaces contoured to conform substantially tothe path of the lead wires along the stator core end face. The wireformer presses against the lead wires to force the lead wires to aposition closer to the stator core end face.

The foregoing and other objects and advantages of this invention willbecome apparent from the following description and the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a fragmentary perspective view of parts of a stator windingmachine in accordance with this invention and illustratesdiagrammatically the manner in which the coil leads extending from thecoils of a freshly wound stator may be handled at a stator coil windingstation.

FIGS. 2 through 5 are each fragmentary perspective views of parts of thestator winding machine of FIG. 1 with the freshly wound stator corelocated at a stator coil lead anchoring and cutting station and show, insequence, different stages in the anchoring of stator coil lead wirestemporary wire clips by means of a robot partly illustrated therein.

FIG. 6 is a plan view of an improved lead wire tamping blade that may beused in an aspect of this invention.

FIG. 7 is a side elevational view of the improved lead wire tampingblade of FIG. 6 taken along line 7--7 thereof.

FIG. 8 is an end elevational view of the improved lead wire tampingblade of FIG. 7 taken along line 8--8 thereof.

FIG. 9 is an elevational view of a lead wire cutting mechanism that maybe used for cutting the stator coil leads at the stator coil leadanchoring and cutting station. FIG. 9 also shows part of a robot used tooperate the cutting mechanism.

FIGS. 10 and 11 are diagrammatic views of a stator having stator coillead wires accurately trimmed in accordance with this invention.

FIG. 12 is a side elevational view of an alternate temporary wire clipthat may be used in place of the temporary wire clip shown in FIGS. 2through 5.

FIG. 13 is a top plan view of a lower base portion forming part of thealternate temporary wire clip shown in FIG. 12.

FIG. 14 is a top plan view of an upper jaw forming part of the alternatetemporary wire clip shown in FIG. 12.

FIG. 15 illustrates a prior art robot end effector having opposedgripping jaws.

FIG. 16 is a top plan view of an improved wire-guiding tooling member inaccordance with this invention that may be used in place of the opposedgripping jaws shown in FIG. 15.

FIG. 17 is an enlarged, fragmentary plan view of a portion of thewire-guiding tooling member shown in FIG. 16.

FIG. 18 is a fragmentary side elevational view of the portion of thewire-guide tooling member shown in FIG. 17 taken along line 18--18thereof.

FIG. 19 is a cross-sectional view of the wire-guide tooling member ofFIG. 18 taken along line 19--19 thereof.

FIG. 20 is cross-sectional view of the wire-guide tooling member of FIG.18 taken along line 20--20 thereof.

FIG. 21 is a fragmentary perspective view of a portion of a robot endeffector, as shown in FIG. 15, modified to include a pair of opposedwire-guiding tooling members, as shown in FIGS. 16 through 20,operatively-engaged with a lead wire.

FIG. 22 is a side elevational view showing a coil lead wire in theprocess of being operatively engaged or "hooked" by an end effectorusing the end effector tooling shown in FIGS. 16 through 21. FIG. 22also shows a wire-guiding ledge in accordance with this invention.

FIG. 23 is a top plan view the wire-guiding ledge shown in FIG. 22.

FIG. 24 is a front elevational view of the wire-guiding ledge of FIG. 23looking in the direction of arrows 24--24 of FIG. 23.

FIG. 25 is a side elevational view of the wire-guiding ledge of FIG. 23looking in the direction of arrows 25--25 of FIG. 23.

FIGS. 26 through 28 are perspective views similar to FIGS. 1 and 2 of asecond embodiment of a stator winding machine in accordance with thisinvention which includes the preferred end effector jaws of FIGS. 16through 21 and ledges as shown in FIGS. 23 through 25, and sequentiallyillustrate the coursing of a coil lead wire around a stator end face andthe subsequent precision trimming thereof.

FIG. 29 is a perspective view similar to FIGS. 1 and 26 of a third, andpresently preferred, embodiment of a stator winding machine inaccordance with this invention, including preferred embodiments of awire-guiding ledge, temporary wire clamps, and lead wire anchors.

FIG. 30 is an exploded perspective view of the wire-guiding ledge ofFIG. 29.

FIGS. 31 and 32 are exploded perspective views, respectively, of twodifferent temporary wire clamps forming part of the machine of FIG. 29.

FIG. 33 is a fragmentary elevational view of a portion of the machineshown in FIG. 29 and illustrates a coil lead wire being secured to alead wire anchor in accordance with the preferred embodiment of thisinvention.

FIG. 34 is an fragmentary, exploded perspective view of a portion of animproved lead pull assembly in accordance with this invention.

FIG. 35 is a fragmentary, cross-sectional view of a portion of theimproved lead pull assembly shown in FIG. 34.

FIG. 36 is a top plan view of a wire former assembly in accordance withthis invention showing wire forming tooling forming a part thereof in aninoperative, out-of-the-way position.

FIG. 37 is a side elevational view of the wire former assembly of FIG.36, but showing the wire forming tooling forming a part thereof in anoperative, upright position.

FIG. 38 is an end elevational view of the wire former assembly of FIG.37 taken along line 38--38 thereof with portions shown in broken lines.

DETAILED DESCRIPTION

FIGS. 1 through 5 illustrate a method in accordance with this inventionfor manufacturing a stator 30. In FIG. 1, a pair of coils C1 and C2 havebeen wound on the stator 30 at a winding station, as described incommonly owned U.S. Pat. Nos. 5,185,405 and 5,370,324, which areincorporated herein by reference. (It will be noted that certain aspectsof this invention may be utilized with a winding station as described inU.S. Pat. No. 5,090,108, which is incorporated by reference.) The uppercoil C1 has a pair of coil lead wires, namely a start wire S1 and afinish wire F1, extending therefrom which are inserted into temporarywire clamps 32 at the winding station with the assistance of lead pullassemblies 100, as will be described, and tamping blades, as describedin commonly-owned PCT publication WO 96/34446, published Oct. 31, 1996,which is incorporated herein by reference. Although flat tamping bladesas illustrated in the '866 application and the WO 96/34446 publicationperform satisfactorily in many instances, it is presently preferred toutilize generally T-shaped tamping blades 33 as shown in FIGS. 6 through8, which provide a larger wire-engaging surface on each tamp blade 33.The T-shaped blades 33 are in an upright orientation for the upperclamps 32 and in an inverted orientation for the lower clamps 32. Astart wire S2 and a finish wire F2 of the lower coil C2 are similarlyinserted into other temporary wire clamps 32. The temporary wire clamps32 may be constructed in accordance with commonly-owned U.S. Pat. No.5,495,659, which is incorporated herein by reference.

FIG. 2 illustrates the stator 30 at a robot connect or robot wirehandling station wherein the start wire S2 of the lower coil C2 isgripped by the end effector 34 of a conventional three axis,programmable industrial robot and removed from its temporary wire clamp32. The end effector 34 courses the start wire S2 around a plurality ofposts 36 or other wire support members on the end face of the stator 30.After the start wire S2 is so coursed, the end effector 34 draws thewire radially outwardly of the stator 30 to insert the start wire S2into a temporary wire clamp or clip 38. Thereafter, the end effector 34,which includes a cutter 35 as well known, is moved to a predeterminedposition relative to the stator 30 to accurately trim the start wire S2as it is held in the clip 38. Alternatively, the lead wires may betrimmed using spring-biased cutters 200 carried by the wire clips 38,the cutters 200 being operated by appropriate movements of the endeffector 34, as shown in FIG. 9.

With reference to FIGS. 3 through 5, the finish wire F2, the start wireS1, and the finish wire F1 are similarly coursed around the stator endface by the end effector 34, inserted into a temporary wire clip 38, andaccurately severed by the end effector 34 at a predetermined positionrelative to the stator 30. It will be noted that the particular statorconfiguration shown is FIGS. 1 through 5, which is merely illustrative,results in the start wire S2 being inserted into a separate temporarywire clip 38. Of course, the particular temporary clip 38 in which acoil lead wire is inserted will depend upon the particular configurationof the stator being manufactured. In any case, each coil lead wire willbe inserted into one of the four temporary wire clips 38, which permitsthe end effector to be moved to a predetermined radial distance from thecenter of the stator to trim the lead wire.

FIGS. 10 and 11 diagrammatically illustrate the result of theabove-described method in that the coil lead wires are each accuratelytrimmed at a predetermined position relative to the stator 30. In FIG.10, the coil lead wires are trimmed at a predetermined distance from theouter margin of the stator core which, as illustrated, is non-circular.FIG. 11 illustrates the coil lead wires trimmed at a predetermineddistance from the center axis of the stator core. In either case, thecoil lead wires are trimmed at a precise predetermined location relativeto the stator core. Although FIGS. 10 and 11 show the coil leadsextending to different circumferential locations around the stator, itwill be understood, as mentioned above, that the circumferentiallocation of each coil lead is dependent upon the particular statorconfiguration and forms no part of this invention.

The temporary wire clips 38 may be constructed similarly to the wireclamps 32 in accordance with the aforementioned '659 patent, or they maybe constructed as shown in FIGS. 12 through 14 hereof. FIGS. 12 through14 illustrate an alternate temporary wire clip 40. The wire clip 40 isformed from nylon and includes a fixed base 42 and a somewhat flexible,self-biasing clip jaw 44 connected thereto. A self-biasing hinge 46 isformed on the clip jaw 44 by providing an area of reduced thickness. Asa result, the wire clip 40 does not require an air actuator or the like(not shown) for operation. In addition, the wire clip 40 has a lowprofile, which is beneficial in inserting the coils lead wires into thetemporary wire clips 40 for trimming. As common, the clips 40 aresecured to a support plate 70 (FIG. 1) by a pair of screws (not shown).

With reference to FIG. 15, the end effector 34 may be conventional, inwhich case it includes a pair of opposed, movable gripper jaws 50 and52. The coil lead wires are individually gripped between the jaws 50 and52 and manipulated by movement of the end effector 34 to follow apredetermined path along the stator end face. However, in manyinstances, the desired paths of the coil lead wires along the stator endface are so complex and circuitous that a conventional end effector 34with opposed gripping jaws 50 and 52 is not capable of coursing the leadwires as desired.

FIGS. 16 through 21 illustrate improved end effector wire-guidingtooling members 60 and 62 which are preferably used in place of theconventional gripper jaws 50 and 52, the wire-guiding tooling member 62being a mirror image of the wire-guiding tooling member 60. Inaccordance with this invention, the jaws 60 and 62 havemutually-confronting C-shaped free ends 64 which, when closed together,form a ring or eyelet 66 (FIG. 21). Alternatively, the C-shaped ends 64may have a greater length, in which case they form, when together, acylindrical tube (not shown), the tube and the eyelet 66 beingequivalent for purposes of this invention. The wire-guiding toolingmembers 60 and 62 also have confronting cutter blades 68 that, asapparent, are used to sever the coil lead wires after they are insertedinto the temporary wire clips 38 or 40, as described above.

With particular reference to FIG. 21, the eyelet 66 formed at the freeend of the wire-guiding tooling members 60 and 62, when closed, permitsthe coil lead wires to be coursed around complex and circuitous paths onthe stator end face. The C-shaped members 64 are first aligned with andthen closed around a lead wire extending from a stator coil to atemporary wire clamp 32 so that the lead wire passes through theresulting eyelet 66. As the end effector 34 is moved to manipulate thelead wire, the lead wire is bent slightly around the margin of theeyelet 66 opposite the direction of motion of the end effector 34, asindicated by the arrows in FIG. 21. As a result, the lead wire closelyfollows the complex and circuitous movements of the end effector.

A concern may arise that the lead wires could be damaged if the junctionbetween the C-shaped ends 64 of the wire-guiding tooling members 60 and62, when they are brought together to form the eyelet 66, is not smooth.To overcome such concern, it is contemplated that the robot will notonly be able to operate along three axes, but that it may also have awrist capable of rotational movement. Thus, the wrist could be operated,depending on the direction of movement of the end effector 34, so thatthe lead wires remain within the bight of one of the C-shaped ends 64,rather than at the junction of the ends 64.

Another concern that may arise is the ability of the end effector 34forming the eyelet 66 to draw the coil lead wires into the wire clips38, which are biased in a closed position. The concern arises due to thenominal drag on the coil lead wires as when they are trapped within theeyelet 66. A possible solution would be to provide some means, such asair actuators for example, to open the wire clips 38, therebyfacilitating the easy insertion of the coil lead wires therein.

In a typical stator manufacturing apparatus such as shown in theaforementioned '405 and '324 patents, the temporary wire clamps 32 aremounted on a support plate 70 (FIG. 1). The coil lead wires typicallyextend from the coils C1 and C2 to the temporary wire clamps 32 at asmall or flat angle relative to the plane of the support plate 70 and,in some cases, substantially parallel to the support plate 70. Whenusing the preferred end effector wire-guiding tooling members 60 and 62,a small or flat angle between the plane of the support plate 70 and thecoil lead wires may cause difficulty in forming the eyelet 66 around thecoil leads. This difficulty arises because the C-shaped ends 64 of thewire-guiding tooling members 60 and 62 lie in a plane parallel to thesupport plate, i.e. the eyelet passageway or aperture extendsperpendicular to the support plate 70. Thus, it is difficult to alignthe end effector 34 with the coil lead wires such that they extendthrough the bights of the C-shaped ends 64, which would permit theC-shaped ends 64 to be closed around the coil lead wire with the wirepassing through the resulting eyelet 66.

To permit the coil lead wires to be more readily enclosed within theeyelet 66, it is desirable to have at least a portion of the coil leadsextending from their respective coils at an artificially steep anglerelative to the support plate 70. With reference to FIG. 22, a ledge 80is secured to and extends outwardly from the support plate 70. A coillead wire, which is the start wire S2 of the coil C2 in FIG. 22, extendsover or around the ledge 80 and into its temporary wire clamp 32. Thefinish wire F2 similar extends over or around the ledge 80 and an upperledge 80 (FIG. 26) similarly controls the path of the start wire S1 andthe finish wire F1 of the upper coil C1. As a result, the coil leadwires extend outwardly away from the support plate 70, around the ledges80, and then inwardly into the temporary wire clamps 32. Becauseportions of each of the coil lead wires extend away from the supportplate 70 at a relatively steep angle, the end effector 34 can bepositioned as shown in FIG. 22 so that the selected coil lead wire willextend through the bight of the C-shaped ends 64 of the end effectorwire-guiding tooling members 60 and 62, thereby permitting the eyelet 66to be formed with the selected coil lead wire trapped therein.

In order to permit the coil lead wires to be repeatably enclosed withinthe eyelet 66, it is critical that the coil lead wires extend from thecoils C1 and C2 to the temporary wire clamps 32 along the same, precisepaths from one stator to the next. With reference to FIGS. 23 through25, which show one of the ledges 80 in detail, the ledges 80 may havedowel pins 82 projecting about 1/8" to 3/16" from the front edgethereof, one for each associated temporary wire clamp 32, to ensureprecise location of the coil lead wires. As well known, the coil leadwires are inserted into the temporary wire clamps 32 at the windingstation by use of lead pull assemblies 100, such as shown in the '405and '324 patents. Other examples of a lead pull assembly are shown incommonly-owned U.S. Pat. Nos. 5,413,403 and 4,074,418, which areincorporated herein by reference. A lead pull assembly 100 grips eachcoil lead wire and then swings radially outwardly away from the centerof the stator 30 until the coil lead wire extends radially outwardly ofthe associated dowel pin 82 projecting from the associated ledge 80. Thelead pull assembly 100 then swings in a reverse direction to draw thecoil lead wire against the dowel pin and then into alignment with itstemporary wire clamp 32. Because the coil lead wire is drawn against thefixed dowel pin 82, the coil lead wire extends along substantially thesame precise path, relative to the stator, from one stator to the next,thereby permitting the programmable end effector 34 to repeatably formthe eyelet 66 around the coil lead wire.

With reference to FIGS. 34 and 35, although the lead pull assembly 100may be constructed as shown in the patents mentioned in the precedingparagraph, it is presently preferred to use an improved lead pullassembly 100, a lower end portion of which is illustrated in FIGS. 34and 35. As well known to one skilled in the art, a typical lead pullassembly 100 includes a lead pull rod 102 having a lower end portionterminating in a upwardly-facing, hook-like, U-shaped jaw 104 whichengages a strand of wire to be manipulated (not shown). However, if aslack condition occurs in the strand of wire due to the particularmovements of the lead pull assembly 100, for example, the wire can moveoutwardly of the bight of the jaw 104 along the rod 102, in which casethe lead pull assembly's grip on the wire is lost.

As shown in FIGS. 34 and 35, the preferred lead pull assembly 100 isprovided with a pivotal finger 106 having a downwardly-facing hookportion 106A that retains the strand of wire in the bight of the jaw104. The finger 106 is pivotally mounted in a longitudinal L-shaped slot107 at the lower end of the rod 102 by a roll pin 108, which defines thepivot axis of the finger 106. A compression spring 110 is partlyreceived in a recess 111 in the body of the finger 106 and is trappedbetween the finger 106 and the rod 102, as shown in FIG. 35. Of course,it will be recognized that other resilient biasing members could be usedin place of the compression spring 110. As evident, the spring 110biases the finger 106 toward the position shown in FIG. 35 to close thejaw 104.

As apparent from FIG. 35, a longitudinally-downward force applied to thehook portion 106A of the finger 106 will overcome the bias of the spring106, thereby causing the finger 106 to be cammed and pivoted to anout-of-the-way location so that the strand of wire can be inserted intothe bight of the jaw 104. However, once the wire is so located, thefinger 106 will retain the wire in the bight of the jaw 104 if a slackcondition occurs in the strand of wire.

As also well known in the art, the lead pull assembly 100 furtherincludes a wire holding and cutting mechanism comprising a wire holder112 and a cutting blade 114, fragments of which are showndiagrammatically in FIG. 35 and 36 and the details of which areunimportant for purposes of this invention. The wire holder 112 and thecutting blade 114 are driven downwardly relative to the lead pull rod102 by an air actuator (not shown) to hold and sever a wire held in thejaw 104, the holder 112 trapping the wire against the jaw 104 and thecutting blade 114 severing the wire. Although the finger 106, when inits normally-biased position, blocks access to the bight of the jaw 104,the wire holder 112 engages and cams the finger 106 to an out-of-the-wayposition, thereby permitting the holder to trap the lead wire againstthe jaw 104 for severing by the cutting blade 114.

Referring now to FIGS. 26 through 28, which are similar to FIGS. 1 and2, the coursing of a coil lead wire around the stator end face and thesubsequent precision trimming thereof using the preferred end effectorhaving wire-guiding tooling members 60 and 62 in conjunction with theledges 80 and dowel pins 82 are shown. FIGS. 26 through 28 alsoillustrate an alternative support plate 70A having the wire clips 38located on islands 39. The operation of the respective components shownin FIGS. 26 through 28 will be evident from the foregoing discussion.

FIG. 29 illustrates a presently preferred embodiment of this invention.In general, the structures illustrated in FIG. 29 are similar tocorresponding structures discussed above, but certain modificationsshown in FIG. 29 have been found to be desirable.

With regard to FIGS. 29 and 30, a modified ledge 80 is shown thatincludes a central notch 84 in the front surface thereof and a centralnotch 86 in the rear surface thereof. The front notch 84 providesclearance for a wire former assembly which will be discussed below. Therear notch 86 provides an opening 88, best shown in FIG. 29, throughwhich winding form retainers (not shown) are inserted to secure windingforms (not shown) to the stator core during the coil winding process.

In addition, the dowel pins 82 projecting from the ledge 80 shown inFIGS. 22 through 25 are replaced in FIG. 29 by wire-retaining hooks 90.The hooks 90 are press-fit into apertures 92 formed in the ledge 80 andfit into notches or reliefs 94 formed in the front surface 96 of theledge 80, which reliefs 94 provide key surfaces to prevent rotation ofthe hooks 90 relative to the ledge 80. The apertures 92 areeccentrically located within the reliefs 94, and posts 98 of projectingfrom the hooks 90 are likewise offset toward one side of the hooks 90.As a result, the hooks 90 can only be inserted into the apertures 92 sothat they face outwardly toward a side of the ledge 80, as shown inFIGS. 29 and 30.

As best seen in FIG. 30, the hooks 90 are formed with cam surfaces 99.As a lead wire is moved radially outwardly past a hook 90, as describedabove with regard to the dowel pins 82, the lead wire is cammed over thehook 90 by the cam surface 99 thereon. When the lead wire is then drawnin a reverse direction to be inserted into a temporary wire clamp 32,the wire is trapped or caught within the bight of the hook 90, as shownin FIG. 29. Here, it will be noted that FIG. 29 also differs frompreviously described figures in that the start wire S1 is looped arounda hook 90 to the left of the stator, as shown in FIG. 29, and then drawntoward and inserted into the right-most clamp 32. Likewise, the finishwire F1 is looped around the right-most hook 90 and then drawn towardand inserted into the left-most wire clamp 32. The start and finishwires S2 and F2 of the lower coil C2 are similarly connected to wireclamps 32. Extension of the coil leads to opposite wire clamps 32provides leads of sufficient length to follow the desired paths on thestator core without requiring unduly long stretches of wire extendingpast the temporary wire clamps 32.

With particular regard to the wire clamps 32, it is preferred that thewire clamps 32 be constructed as shown in FIGS. 31 and 32, depending onthe location of the clamp 32 relative to the stator 30. The wire clamps32 shown in FIGS. 31 and 32 are substantially similar to the clampsdescribed in the aforementioned U.S. Pat. No. 5,495,659 and include afixed jaw 72 and a pivotal jaw 74 biased by a spring 76 held in place bya set screw 77. However, it is desirable to make certain modificationsshown in FIGS. 31 and 32. For example, it will be noted that the fixedjaw 72 of the presently preferred clamp 32 does not have a chamferednose as shown in the '659 patent. Also, the upper left-most pair of wireclamps 32 and lower right-most pair of wire clamps 32, as viewed in FIG.29, are each preferably formed with a shortened pivotal jaw 74, as shownin FIG. 31. (FIG. 32 shows a longer pivotal jaw 74 which is used withthe upper right-most and lower left-most pairs of clamps 32.) Suchshortened pivotal jaws 74 on the upper left-most pair and lowerright-most pair of clamps 32 are necessary to avoid interfering withmovements of the lead pull assembly 100 needed to insert the lead wiresinto such wire clamps 32.

FIGS. 31 and 32 also illustrate a transverse slot 78 formed in thewire-engaging surface of the fixed jaw 72 of each wire clamp 32. Thetransverse slot 78 in each clamp 32 is provided to retain the lead wirein the wire clamp 32 immediately after it has been inserted or "stuffed"therein by a tamp blade 33 (FIGS. 6 through 8), as described above. Ithas been found that without the transverse slot, the lead wire tends towithdraw from the wire clamp 32 as the tamp blade 33 is withdrawn, inpart because the clamp 32 does not fully close until the tamp blade 33is no longer between the jaws 72 and 74. Using a preferred clamp 32, asshown in FIGS. 31 and 32, a lead wire inserted into the clamp 32 movesinto the transverse slot 78 in the fixed clamp jaw 72 and is thusretained as the tamp blade 33 is withdrawn.

With reference to FIGS. 29 and 33, the apparatus shown therein is alsomodified to replace the wire clips 38 or 40 shown in FIGS. 1 through 5,12 through 14, and 26 through 28. In place of the wire clips 38 or 40, aplurality of wire-wrapping posts 120 are provided in fixed relation tothe stator 120. Instead of inserting the lead wires into wire clips 38or 40 after they have been coursed along the stator end face by use ofthe above-described robot end effector 34, each lead wire is partlywrapped or looped around the shaft of one of the posts 120, as shown inFIG. 33. The location of each post 120 and the particular post 120 usedwith each lead wire is dependent upon the particular configuration ofthe stator being manufacture. A lead wire so looped around a post 120 istemporarily held in place by the "memory" present in the metal wire.After a lead wire is looped around a post 120, it is released by therobot end effector 34 and then trimmed at a predetermined distance fromthe stator core, as described above.

The use of wire-wrapping posts 120 in place of the wire clips 38 or 40obviates the concern mentioned above regarding the nominal drag on alead wire enclosed within the end effector eyelet 66 and its effect onthe ability of the end effector 34 to insert the lead wire between thejaws of a clip 38 or 40.

As best seen in FIG. 29, each of the posts 120 preferably includes anenlarged head 122 at the free end thereof which prevents the partiallylooped wire from slipping over the free end of the post 120. Theillustrated posts 120 are simple socket-headed screws threaded intosupport plates 124, which are in turn attached to the upstanding supportplate 70A by screws 126. Of course, other post configurations could beused.

FIGS. 36 through 38 illustrate a wire former assembly, generallydesignated 300, in accordance with this invention, which is used topress the lead wires extending along the stator core end face againstthe stator core end face. In accordance with this invention, the wireformer assembly 300 is located at the wire handling station andcomprises wire forming tooling 302 having surfaces 304 contoured toconform to the paths of the stator coil lead wires that have beencoursed along the end face of the stator core, as described above. (Ofcourse, the wire former assembly 300 could be located at a separatestation.) The configuration of the wire forming tooling 302 shown inFIG. 36 is merely illustrative, it being understood that the particularconfiguration of the wire forming tooling 302 depends upon theconfiguration of the stator being manufactured and forms no part of thisinvention.

The wire forming tooling 302 is carried by a support arm 306fixedly-attached to a pivot rod 308 extending transversely through asupport member 310. The support member 310 is driven linearly toward andaway from a stator core at the wire handling station by a conventional,commercially-available air actuator 312 having a piston rod 314connected to the support member 310. A cam roller 316 is mountedeccentrically at the end of the pivot rod 308 by an extension 318 and isreceived in a guide slot 320 formed in an upstanding support plate 322.The guide slot 302 has an arcuate portion 324 and a linear portion 326.

When the piston rod 314 of the actuator 312 is fully retracted, the camroller 316 is located at lower end of the guide slot 320, and thesupport arm 306 and the wire forming tooling 302 are in anout-of-the-way position, as shown in FIG. 36. As the piston rod 314 isextended, the support member 310 moves toward the stator located at thewire handling station and the cam roller 316 travels along the arcuateportion 324 of the guide slot 320, thereby pivoting the support arm 306and the wire guide tooling 302 to an upright position confronting astator at the wire handling station, as shown in FIGS. 37 and 38. As thepiston rod 314 is further extended, the cam roller 316 travels along thelinear portion 326 of the guide slot 320 and the support arm 306 and thewire forming tooling 302 are translated in their upright position towardand into engagement with the stator. The contoured surfaces 304 are thusdriven into engagement with the lead wires coursed along the stator coreend face to press them into position close to the stator core end face.Thereafter, the piston rod 314 of the air actuator 312 is retracted toreturn the support arm 306 and the wire forming tooling 302 to theirout-of-the-way position shown in FIG. 36.

Although not shown in FIGS. 36 through 38, it is desirable to provide asecond support plate opposite to the support plate 322 to provideadditional support for the support member 310 as it is driven toward andaway from the stator core by the air actuator 312. To this end, thesupport member 310 is formed generally in the shape of an inverted L, asbest seen in FIG. 38, and has a bearing surface 328 which travel along acorresponding bearing surface (not shown) of an upstanding support plate(not shown) opposite the support plate 322. Preferably, the secondsupport plate has a bearing surface formed from lamina bronze.

Although the presently preferred embodiments of this invention have beendescribed, it will be understood that various changes may be madewithout departing from the scope of the following claims.

Having thus described our invention, we claim:
 1. In a method ofmanipulating and severing a lead wire of a stator coil wound on a statorcore, said lead wire extending from said coil adjacent an end face ofthe stator core to a temporary wire clamp, the stepscomprising:enclosing said lead wire within an eyelet; moving said eyeletto remove said lead wire from its temporary wire clamp; moving saideyelet to course said lead wire along a predetermined path along saidend face and radially outwardly of said stator; temporarily anchoringthe free end of said lead wire; and while said free end is temporarilyanchored, severing said lead wire at a predetermined position relativeto said stator.
 2. The method of claim 1 wherein said predetermined pathcomprises a complex, circuitous path.
 3. The method of claim 1 whereinthe step of temporarily anchoring said lead wire is accomplished bymoving said eyelet to draw said wire into a wire clamp.
 4. The method ofclaim 1 wherein the step of temporarily anchoring said lead wire isaccomplished by moving said eyelet to partly loop said lead wire arounda post located remotely from said stator core.